A group of scientists have a radical idea for combating climate change: terraforming the Sahara Desert and replacing it with a lush forest. But will its carbon capturing potential outweigh the negative ecological consequences?

In next month's issue of Climate Change, cell biologist Leonard Ornstein of the Mount Sinai School of Medicine and David Rind and Igor Aleinov of NASA's Goddard Institute for Space Studies outline their plan to plant a forest in the Sahara Desert. They propose desalinating seawater from the desert's nearby oceans, and using aquaducts and pumps to bring it inland. The idea is to plant Eucalyptus Grandis, which survives well in heat, which would be watered using drip irrigation. The trio claim the trees would lower the Sahara's temperature by up to 8°C Celsius in some areas, bring clouds to reflect the sun's rays back into space, and capture eight billion tons of carbon each year.

But the plan is not without its downsides. Aside from the $2 trillion a year price tag, the forest would also likely prevent iron-rich dust from the sands from blowing into the Atlantic Ocean, iron that nourishes marine life. And the increased moisture could bring a plague of locusts down on not just the Sahara, but the rest of Africa as well.